Long Training Field (ltf) in Distributed Transmission

1. A wireless communication device, comprising: at least one processor; and at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor, is configured to cause the wireless communication device to: map a sequence of values representative of a long training field (LTF) of a physical (PHY) layer convergence protocol (PLCP) protocol data unit (PPDU) to a plurality of noncontiguous subcarrier indices of a plurality of subcarrier indices spanning a wireless channel according to a distributed tone plan, wherein the sequence of values is a subset of an LTF sequence that comprises one or more 26-tone base sequences, wherein the one or more 26-tone base sequences form larger base sequences associated with the LTF sequence, and wherein the larger base sequences comprise a first 52-tone base sequence, a second 52-tone base sequence, and a 106-tone base sequence; and transmit the PPDU via the wireless channel, the PPDU comprising the sequence of values mapped to the plurality of noncontiguous subcarrier indices.

2. The wireless communication device of claim 1, wherein the LTF sequence maps to the plurality of subcarrier indices according to the distributed tone plan.

3. The wireless communication device of claim 2, wherein the one or more 26-tone base sequences are each configured for transmission on a respective 26-tone distributed resource unit (dRU) based on a peak-to-average power ratio (PAPR) associated with a transmission of the LTF sequence.

4. The wireless communication device of claim 3, wherein portions of the LTF sequence that map to 26-tone dRUs having same relative pilot tone locations are associated with different base sequences.

5. The wireless communication device of claim 3, wherein the first 52-tone base sequence corresponds to LTFdRU52,1, the second 52-tone base sequence corresponds to LTFdRU52,2, and the 106-tone base sequence corresponds to LTFdRU106, and wherein:, LTF dRU ⁢ 52 , 1 = γ 1 * LTF dRU ⁢ 26 , 1 + γ 2 * LTF dRU ⁢ 26 , 2 ; LTF dRU ⁢ 52 , 2 = γ 3 * LTF dRU ⁢ 26 , 3 + γ 4 * LTF dRU ⁢ 26 , 4 ; and LTF dRU ⁢ 106 = γ 5 * LTF dRU ⁢ 52 , 1 + γ 6 * LTF dRU ⁢ 52 , 2 + LTF add_tones .

6. The wireless communication device of claim 5, wherein: γ1 and γ2 are phase rotations applied to a first 26-tone base sequence (LTFdRU26,1) and a second 26-tone base sequence (LTFdRU26,2), respectively, based on the PAPR associated with the transmission of the LTF sequence; γ3 and γ4 are phase rotations applied to a third 26-tone base sequence (LTFdRU26,3) and a fourth 26-tone base sequence (LTFdRU26,4), respectively, based on the PAPR associated with the transmission of the LTF sequence; and γ5 and γ6 are phase rotations applied to the first 52-tone base sequence (LTFdRU52,1) and the second 52-tone base sequence (LTFdRU52,2), respectively, based on the PAPR associated with the transmission of the LTF sequence.

7. The wireless communication device of claim 5, wherein LTFadd_tones are LTF values on additional tones of the 106-tone base sequence (LTFdRU106), based on the PAPR associated with the transmission of the LTF sequence.

8. The wireless communication device of claim 1, wherein the sequence of values is based on relative locations of the plurality of noncontiguous subcarrier indices in the wireless channel.

9. The wireless communication device of claim 1, wherein the LTF sequence maps to the plurality of subcarrier indices according to a non-distributed tone plan.

10. The wireless communication device of claim 1, wherein, to map the sequence of values to the plurality of noncontiguous subcarrier indices, the processor-readable code, when executed by the at least one processor, is configured to cause the wireless communication device to: modulate the sequence of values on a plurality of tones representative of a logical resource unit (RU) associated with a non-distributed tone plan; and map the plurality of tones to the plurality of noncontiguous subcarrier indices, respectively.

11. The wireless communication device of claim 1, wherein the sequence of values is configured for transmission on an N-tone distributed resource unit (dRU) based on a peak-to-average power ratio (PAPR) associated with a transmission of the dRU.

12. A wireless communication device, comprising: at least one processor; and at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor, is configured to cause the wireless communication device to: receive a physical layer (PHY) convergence protocol (PLCP) protocol data unit (PPDU) via a wireless channel; and demap a sequence of values representative of a long training field (LTF) of the PPDU from a plurality of noncontiguous subcarrier indices of a plurality of subcarrier indices spanning the wireless channel according to a distributed tone plan, wherein the sequence of values is a subset of an LTF sequence that comprises one or more 26-tone base sequences, wherein the one or more 26-tone base sequences form larger base sequences associated with the LTF sequence, and wherein the larger base sequences comprise a first 52-tone base sequence, a second 52-tone base sequence, and a 106-tone base sequence.

13. The wireless communication device of claim 12, wherein the processor-readable code, when executed by the at least one processor, is configured to cause the wireless communication device to: estimate the wireless channel based on the sequence of values.

14. The wireless communication device of claim 12, wherein the LTF sequence maps to the plurality of subcarrier indices according to the distributed tone plan.

15. The wireless communication device of claim 14, wherein the one or more 26-tone base sequences are each configured for transmission on a respective 26-tone distributed resource unit (dRU) based on a peak-to-average power ratio (PAPR) associated with a transmission of the LTF sequence.

16. The wireless communication device of claim 15, wherein portions of the LTF sequence that map to 26-tone dRUs having same relative pilot tone locations are associated with different base sequences.

17. The wireless communication device of claim 15, wherein the first 52-tone base sequence corresponds to LTFdRU52,1, the second 52-tone base sequence corresponds to LTFdRU52,2, and the 106-tone base sequence corresponds to LTFdRU106, and wherein:, LTF dRU ⁢ 52 , 1 = γ 1 * LTF dRU ⁢ 26 , 1 + γ 2 * LTF dRU ⁢ 26 , 2 ; LTF dRU ⁢ 52 , 2 = γ 3 * LTF dRU ⁢ 26 , 3 + γ 4 * LTF dRU ⁢ 26 , 4 ; and LTF dRU ⁢ 106 = γ 5 * LTF dRU ⁢ 52 , 1 + γ 6 * LTF dRU ⁢ 52 , 2 + LTF add_tones .

18. The wireless communication device of claim 17, wherein: γ1 and γ2 are phase rotations applied to a first 26-tone base sequence (LTFdRU26,1) and a second 26-tone base sequence (LTFdRU26,2), respectively, based on the PAPR associated with the transmission of the LTF sequence; γ3 and γ4 are phase rotations applied to a third 26-tone base sequence (LTFdRU26,3) and a fourth 26-tone base sequence (LTFdRU26,4), respectively, based on the PAPR associated with the transmission of the LTF sequence; and γ5 and γ6 are phase rotations applied to the first 52-tone base sequence (LTFdRU52,1 and the second 52-tone base sequence (LTFdRU52,2), respectively, based on the PAPR associated with the transmission of the LTF sequence.

19. The wireless communication device of claim 17, wherein LTFadd_tones are LTF values on additional tones of the 106-tone base sequence (LTFdRU106), based on the PAPR associated with the transmission of the LTF sequence.

20. The wireless communication device of claim 12, wherein the sequence of values is based on relative locations of the plurality of noncontiguous subcarrier indices in the wireless channel.